Infeed system for a stacking apparatus

ABSTRACT

Groups of individual shingled items such as graham crackers or cookies are stacked in vertical stacks of predetermined heights and/or number of items using a stacking apparatus having at least one set of lowering arms. A stacking conveyor belt continuously delivers groups of shingled items to the end of the conveyor where the items come into contact with the lowering arms. The lowering arms then gently lower shingled items to a lower stacking level while forming a vertical stack. The items in the stack remain in substantially horizontal position while being lowered from the stacking conveyor to the lower stacking level. The apparatus is substantially jam-free and is highly tolerant to irregular placement of the shingled items on the stacking conveyor. The stacking apparatus can be used for stacking of groups of shingled items of different size and/or weight with little or no modification. The stacking apparatus may include an infeed system for delivering groups of shingled items to the stacking conveyor at regular intervals. The infeed system is capable of receiving items in the same direction or at a right angle to the flow of the infeed system. Items delivered at a right angle to the flow of the infeed system are received by a tilt conveyor adopted to gently receive breakable and fragile items with virtually no impact or damage to the items.

This application is a divisional application of U.S. Ser. No.09/610,248, filed Jul. 5, 2000, now U.S. Pat. No. 6,543,989, which is autility application of provisional application U.S. Ser. No. 60/142,450,filed Jul. 6, 1999.

FIELD OF THE INVENTION

The invention relates to a method and a stacking apparatus for stackingvarious shingled items such as crackers or cookies moving on a conveyorbelt into vertical stacks of predetermined heights or number of items.The invention further relates to infeed systems for delivering of groupsof shingled items to stacking apparatus that comprises a receiving tiltconveyor.

BACKGROUND OF THE INVENTION

In the large scale production of wrapped or unwrapped products, such asfood items, tiles, compact disks (CDS) or other relatively flat productsor packages it is often desirable to arrange groups of individual itemsinto vertical stacks for further wrapping or packaging the verticalstacks of the items into larger trays or containers.

Vertical stacks comprising loose individual items such as crackers,cookies, tiles or small packages or bags stacked upon each other can beproduced manually or by using various stacking methods and apparatus.Sometimes, it is advantageous to arrange individual items in a shingledmanner prior to stacking of individual items into vertical stacks foreasier formation of vertical stacks, or for other considerations intheir manufacture. Shingled items are usually delivered to a stackingapparatus in groups or in a continuous stream on a conveyor. Shinglingof loose items may be achieved by using several conveyors arranged inseries and moving at various speeds which are continuously fed with astream of loose items. The loose items are delivered to the series ofconveyors which place the items in a shingled arrangement from anotherlocation. The items are usually delivered to the first conveyor in theseries of shingling conveyors by another conveyor moving in the samedirection or transverse direction to the flow of the series of shinglingconveyors.

Apparatus for stacking shingled items is disclosed, for example, in U.S.Pat. No. 2,708,863 to Payne. Shingled items are delivered via a conveyorinto a vertical stack with the aid of movable stop fingers that rise upto prevent forward movement of items, thus causing shingled items topile on top of each other forming a vertical stack. After a verticalpile is formed, the fingers lower to allow continuous forward movementof the vertical stack.

U.S. Pat. No. 3,088,604 to Nilsson discloses stacking shingled items(newspapers) into vertical stacks on a support platform and transportingthe stacks on the support platform to another conveyor.

U.S. Pat. No. 3,124,059 to Labombarde discloses stacking of shingleditems into vertical stacks. Shingled items delivered by a conveyor falldown a chute. The items are guided by rollers to fall flat withouttilting.

U.S. Pat. No. 3,195,739 to Hein et al., discloses a piling device thatmoves and stacks items from an upper platform to a lower table by usingswinging arms that pick up the items at the end of an upper platform andslide them to a lower level.

U.S. Pat. No. 3,331,516 to Gubeli discloses a method and apparatus forstacking of shingled items delivered by a conveyor, into vertical piles(stacks) wherein shingled items fall down the chute at the end of theconveyor. Their movement is guided by a pressure rail at the end of theconveyor.

U.S. Pat. No. 3,403,033 to Griner discloses shingling of flat biscuitswherein pieces arrive in a flat position and are separated from eachother, stacked in tilted overlapping position and then innon-overlapping completely vertical edge position for packing.

U.S. Pat. No. 3,429,416 to Provost et al, discloses a transfer conveyorapparatus for delivering rows of articles to several infeed conveyorsmoving at a right angle to the transfer conveyor.

U.S. Pat. No. 3,488,917 to Oswald et al. discloses transportation andpacking of shingled book matches. A wiper blade prevents shingledproducts from falling down when a carriage intermittently movesbackwards.

U.S. Pat. No. 3,638,538 to Sullivan discloses stacking of shingled itemsinto vertical piles. After a predetermined number of items has beencounted, a vertical stopper arm is moved upward and forward to move theitems toward the closed door stacking them into a vertical position. Thearms drop down sharply when they reach the end point and the items arein a complete vertically stacked position. The door is then open toallow the stacked items to be moved to another transporter. The armsmove shingled items to a stopper door, densifying the stack along theway and eventually stacking items in completely vertical stacks.

U.S. Pat. No. 3,874,522 to Rana discloses converting of a loose shinglestack of signatures (any flat products) into a dense stack of shingledsignatures.

U.S. Pat. No. 4,282,964 to Hogenkamp et al, discloses a device fortransferring articles arriving in transverse rows on an upper conveyorto a lower removal belt. The device comprises a transfer belt pivotallymounted for alignment with the plane of the delivery belt and the planeof the removal belt.

U.S. Pat. No. 4,432,685 to Stauber discloses an overhead stop plate. Ina prestacker that stacks products arriving as shingled piles viaconveyor to the prestacker, the product falls down a chute formingvertical stacks. However, before falling, each single piece of producthits a stop plate that stops the piece from moving forward and guides itto fall down the chute.

U.S. Pat. No. 5,095,684 to Walker et al. discloses an apparatus forconveying individual, flat laying products (such as cookies) from ahorizontal position to shingled overlapping stacks and to a completelyvertical edge position using several conveyors moving at differentspeeds. The speed is varied depending on the heights of the cookies. Thecookies are counted, and a predetermined number of cookies, incompletely vertical position are then packaged in cookie trays. Stackingshingled products in a horizontal position in vertical stacks (on top ofeach other) is not disclosed.

U.S. Pat. No. 5,287,952 to Radaelli discloses a device for transferringof rows of items from an upper conveyor belt to a lower conveyor beltarranged at a right angle. The device comprises two intermediateshelves. The first shelf is pivotally mounted to align with the end ofthe downward inclined upper conveyor to receive rows of items byinclining upwards. Then, it is aligned in a horizontal position with thesecond shelf to transfer the rows of items to the horizontal secondshelf. The second shelf then moves downward for alignment with the edgeof the lower conveyor and to transfer rows of items to the lowerconveyor.

U.S. Pat. No. 5,460,843 to Greene discloses a device for packagingcookies. Prior to packaging, the cookies are dropped to a lower levelconveyor with the help of an overhead belt system that orients cookiesinto a vertical position. The last cookie of each stack with apredetermined number of cookies is inverted. The cookies are thenstacked in vertical position in stacks and packaged with the last cookiebeing inverted and facing an opposite direction compared to the rest ofthe stack.

U.S. Pat. No. 5,640,833 to Gerber discloses a device for transferringitems from a supply belt on a transverse belt. The device comprises anintermediate supply conveyor belt with a tilting end for alignment withthe surface of the transverse belt for gentle discharging items onto thetransverse belt.

None of the stacking apparatus for forming vertical stacks from groupsof shingled individual items disclosed in the cited references teach orsuggest apparatus comprising lowering arms, or beams, that gentlytransport items to be stacked to a lower stacking level, wherein theitems remain in a substantially horizontal position while being loweredby the lowering arms, and the bottom item of the forming stack remainson the lowering arms in substantially horizontal position during theentire time it remains in contact with the lowering arms. Also thereferences do not disclose an infeed system comprising a series ofconveyors for shingling and separating a stream of items into groups ofpredetermined number which employs a tilting conveyor for gentlereceiving of groups of items.

The present invention provides a method for producing vertical stacksand a stacking apparatus comprising at least one set of lowering arms orbeams that lower items continuously delivered by an infeed conveyorsystem in shingled groups, to a lower stacking level, while formingvertical stacks. The items remain in an at least substantiallyhorizontal position all or substantially all the time during thestacking cycle. The infeed system, comprising a series of conveyorsmoving at various speeds, is capable of gently: a) receiving itemsdelivered to the infeed system in the same direction, or at a rightangle to the direction of the flow of the infeed system, b) breaking thestream of items into groups of predetermined number, c) shingling theitems in the groups, and d) delivering groups of shingled items to thestacking apparatus at regular intervals synchronized with the stackingcycle of the lowering arms. The apparatus allows for efficient and easyhandling of large numbers of items per minute. It can be used withlittle or no adjustment to handle items of different shape, can beeasily adjusted to handle groups of items containing different numbersof items per group, and is virtually jam-free. It is also very gentle onthe items being stacked. The apparatus is highly tolerant to misorientedor irregularly placed items, irregularly shaped or broken items, and iscapable of curing most of the misorientations and other irregularitiesduring the stacking process to form regularly shaped stacks.

SUMMARY OF THE INVENTION

The invention provides a method and apparatus for stacking groups ofshingled items, such as food items, into vertical stacks. The stackingapparatus includes at least one set of lowering arms capable oftransporting groups of items from a delivery conveyor system or aconveyor belt to a lower stacking position while forming the groups ofitems into vertical stacks. The bottom or leading item of each group ofshingled items remains in contact with the lowering arms while theforming stack is being transported from the conveyor belt to the lowerstacking position. Also, each item in the group remains in substantiallyhorizontal position during the stacking process. Vertical stacks of apredetermined height are formed from groups containing a predeterminednumber of individual items that have been placed in a shingledarrangement by an infeed system. The infeed system delivers the group ofitems in a shingled arrangement to the input end of the stackingapparatus. The infeed system includes a series of successive conveyorsthat operate at variable speeds to arrange the items in shingled groupsof predetermined number The infeed system also provides wide space gapsbetween the groups to allow the stacker to complete one stacking cycleimmediately before the next group of items reaches the stacking oroutput end. The infeed system may further include a receiving conveyorto receive items delivered at a right angle to the flow of the infeedsystem. The receiving conveyor may be a tilt conveyor which isspecifically adopted for receiving fragile or breakable items whileminimizing impact and damage to the items.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a shows a schematic side view of a stacking apparatus forstacking groups of individual shingled food items, such as grahamcrackers, with the lowering arms in an upper position.

FIG. 1 b shows the lowering arms of FIG. 1 a lowering a vertical stackof graham crackers, wherein crackers are arranged in a horizontalposition.

FIG. 1 c shows the lowering arms of FIG. 1 a in the retracting positionafter releasing a vertical stack of crackers placed on a lower stackinglevel.

FIG. 2 shows a schematic perspective view of a stacking apparatus andinfeed conveyor system including an infeed tilt conveyor.

FIG. 3 shows a strip conveyor positioned at a right angle to the infeedsystem and tilt conveyor of FIG. 2 for right angle strip transfer.

FIG. 4 shows a cross-sectional view of the tilt conveyor of FIG. 3accepting items delivered by the strip conveyor.

FIG. 5 shows a profile of the tilt conveyor of FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a lowering arm stacking apparatus forstacking various individual items into vertical stacks of predeterminedheights. Stacking apparatus allows for transfer of goods, continuouslydelivered by a conveyor system in groups having a shingled arrangement,from the conveyor system to a lower stacking position while maintainingthe goods in an at least substantially horizontal position. It minimizesimpact of placing or dropping of one item on top of another item to forma stack. The groups of items are discharged from the lowering arms tothe lower stacking level without sliding or rolling off the loweringarms which minimizes abrasive damage or breakage to the stacked items.The stacking apparatus requires no or little modification or adjustmentto handle items of various size and weight, loose individual items orpackaged items. The apparatus of the invention may be employed forstacking, for example, food items that range from small individualcrackers, such as graham crackers or cookies to boxes of frozenvegetables, packaged goods. Non-food items such as CD's or even vinylflooring tiles or ceramic tiles, may also be stacked providing that theitems enter the stacking end of the apparatus in groups of shingledarrangement.

The apparatus of the present invention comprises an upper conveyorsystem, such as a stacking conveyor belt having two ends: 1) an iteminput end, i.e., the end where the groups of shingled items are loadedon the belt, and 2) an item delivery end, i.e., the end where thetransported items are disposed or transferred from the conveyor andcollected in vertical stacks. The stacking conveyor belt continuouslydelivers the items that require stacking to the delivery end where theitems come into contact with the lowering arms, or beams. The loweringarms transfer the stackable items from the stacking conveyor belt to thelower stacking position where the items are collected in verticalstacks. The lower stacking position may be a stationary lower platformwith a pusher plate to push stacks onto another conveyor. In anotherembodiment, the lower stacking position may be a conveyor belt thattransports the formed vertical stacks of items to another location forfurther processing such as wrapping or packaging of stacks in biggercontainers. The lower conveyor belt may travel in a directionsubstantially parallel to the flow direction of the stacking conveyorbelt or normal to it, i.e. at a right angle to it. The lower conveyormay be a simple conveyor belt or may comprise various compartments, flapfingers or other devises to assist transportation of the formed verticalstacks without toppling of the stacks. The lower conveyor belt mayoperate continuously or intermittently in a manner so as to not topplethe stack.

The stacking apparatus may include at least one set of lowering arms,wherein each set comprises two lowering arms. The lowering arms have aflat upper surface and are located adjacent to the upper conveyor belt,one on each side of the conveyor. The arms move in continuous forward,downward, rearward and upward circular paths during one stacking cycle.Movement of both lowering arms within the set are completelysynchronized to exactly duplicate each others movement. Synchronizationof the lowering arms within the set may be achieved using a mechanicalconnection between the beams or electronically. In embodiments using amechanical synchronization, the synchronization of the movements of thelowering arms is achieved by driving the lowering arms or beams with acommon motor.

During one stacking cycle, the lowering arms move 360° or one completefull circular path. The lowering arms move forward and come into contactwith the leading or the bottom item of a group of items duringhorizontal movement of the group at the item delivery end of thestacking conveyor. The arms remain in contact with the bottom itemduring lowering of all the items in the group to the lower stackinglevel. The lowering arms lower the items while moving downward. As thelowering arms move downward and lower items already stacked on the arms,the trailing items sequentially slide into a stacked position on top ofthe preceding item. After the complete stack of items is lowered to thestacking level, the lowering arms retract backward in a circular pathand release items stacked on the lower level. After the items are thuslystripped off the lowering arms, the lowering arms return to their upperposition for receiving the next group of items, thus completing astacking cycle. The lowering arms then move forward to come into contactwith the next item or group of items to be stacked into a verticalstack.

The lowering arms may move with a different speed during the part of thecycle when the arms are in contact with the product and during the partof the cycle when the arms return to the upper position after releasinga stack of items on the lower level. The speed of the lowering armsduring the return part of the stacking cycle is adjusted to maximize theproductivity and stacking efficiency of the apparatus. During thestacking cycle the items remain in at least substantially horizontalposition at least substantially all the time so that slippage or slidingof the items from the lowering arms does not occur and the items aregently loaded onto the lower level platform. The stack is dischargedfrom the lowering arms when the lowering arms retract from the stackloaded onto the lower platform by moving backward and downward so thatthe lower item does not slide or roll off the arms.

In addition to the stacking conveyor belt, the lower stacking platformor conveyor, and at least one set of lowering arms or beams, thestacking apparatus for stacking of shingled items, such as grahamcrackers preferably includes: 1) a guide means or a guide located atleast partially above the stacking conveyor, and 2) a lower stop platefor preventing stacks of crackers from moving backwards.

Groups of shingled crackers comprising a predetermined number ofcrackers are continuously transported via the stacking conveyor belt tothe delivery or exit end of the stacking conveyor. Upon reaching thedelivery end, the leading or the bottom item, which may be a cracker,comes into contact with at least one set of lowering arms. The armscontinuously lower the first cracker while the other crackers, one byone, reach the delivery end and each cracker piles upon the previouscracker thus forming a vertical stack. The guide, located at leastpartially above the delivery end of the stacking conveyor, preventscrackers from moving forward while being placed on top of each other andlowered to the lower level. The guide can be of various shapes, but tominimize the impact of the crackers against the guide and to achieve asliding effect on the crackers, it is preferred that the guide comprisesa curved surface with the radius of the curve being similar or greaterto the radius of the curve of the stacking conveyor at the delivery endof the conveyor. The guide should be located above and away from thedelivery end of the upper conveyor so that the guide: 1) helps to stopthe horizontal movement of the cracker, 2) helps to guide the crackersinto vertical stacks, and 3) allows the forming, vertical stacks ofcrackers to be freely lowered by the lowering arms to the lower stackinglevel platform. Upon reaching the lower level platform or conveyor, thelowering arms release the vertical stack of crackers and retractbackward. The lower stop plate prevents any backward movement of thestack during lowering and discharging of the stack onto a lower stackingplatform. The crackers remain in substantially horizontal positionduring the entire stacking cycle, i.e., from the moment the firstcrackers come into contact with the lowering arms to the moment thecomplete stack is placed onto the lower stacking level and the loweringarms retract from the formed stack. The lowering arms then move upwardand forward to repeat the stacking cycle with another group of shingledcrackers.

The stacking apparatus may further include a pusher plate that pusheseach formed stack away from the stacking conveyor and the lower stackinglevel, and places the stack onto another conveyor that transports thestacks to another location for further wrapping or packaging in suitablepackages.

The position of the lowering arms is timed and adjusted so that thelowering arms reach their uppermost position and align or substantiallyalign with the upper surface of the upper conveyor every time the firstcracker of a shingled group is delivered to the delivery end of theupper conveyor. While in the uppermost position, the lowering arms arepositioned just slightly below the surface of the upper conveyor. Inthis position, the lowering arms should extend beyond the delivery endof the conveyor by a length equal to or greater than the size of theindividual item to be stacked, so that the first item fits across theextended portion of the lowering arms. The lowering arms extend beyondthe delivery end of the upper conveyor during the entire time thelowering arms remain in contact with the stacked items. However thelowering arms should not extend too far beyond the upper conveyor sothat the lowering arms do not intersect the path and interfere with theconveyor that transports the stacked items to another location forpackaging. The precise timing of the position of the lowering armsrelative to the shingled items on the stacker conveyor belt can beachieved by methods known in the art such as by the use of visiondetectors, video cameras, light detectors or photoelectric eyes fordetecting gaps between the shingled groups of crackers.

The stacking conveyor may be fed manually or preferably automatically,with the groups of shingled items by an infeed or loading system. Theinfeed system may be any system that feeds groups of shingled items tothe input end of the stacking conveyor at regular intervals or regularlyspaced from each other. The feeding may be continually orintermittently. In preferred embodiments, the infeed system may includea series of successive conveyors that count the items, separate theminto groups, and shingle them and separate the shingled groups so thatthe groups arrive at the stacking apparatus at regular intervalssynchronized with one stacking cycle of the lowering arms.

The infeed system may include from 3, preferably 4 to 12 or moreconveyors depending on the way the items arrive at the first conveyor,the speed of the overall operation and other factors, such as the sizeof the items. The items may arrive in flat, shingled or horizontal stackarrangements. If they arrive in any other arrangement than flat, theitems are first placed into flat arrangement. The items may also arriveat the infeed system in the flow direction of the infeed system or at aright angle to the flow direction of the infeed system. If the itemsarrive at a right angle, the infeed system comprises an additionalconveyor located at the beginning of the series of conveyors in theinfeed system. This additional, first in the series, or receivingconveyor is necessary for accepting groups or strips of items deliveredat a right angle to the infeed system flow. The receiving conveyortransports the groups of items to the next conveyor of the infeed systemin the direction of the infeed system flow.

Methods for delivering of items at a right angle to the infeed systemflow by right angle strip conveyors are known in the art and arecustomarily used in the transportation of candy bars. Batches or stripsof products may be delivered to the receiving conveyor located at thebeginning of the series of infeed conveyors by a drop gate conveyor. Thetechnology of delivering batches or strips of items at a right angle toan infeed system by drop gate conveyors is known and commonly referredto as “candy bar” delivery technology. During such a delivery of candybars or other batches or strips of items, the items are delivered to thereceiving conveyor at a right angle to the flow of the infeed system viaan overhead conveyor comprising drop gates located above the receivingconveyor of the infeed system. When a strip of items reaches the dropgate, the gate opens by tilting downward to the level just above thelevel of the receiving conveyor of the infeed system, allowing the groupof items to slide to the first conveyor. The overhead conveyor usuallyfeeds several infeed systems or legs located parallel to each other. Assoon as one strip is delivered to one of the receiving conveyors of oneof the infeed systems, the drop gate closes, or moves back to ahorizontal position, and the next strip of items flows to the next dropgate. While this known “candy bar” technology may be employed in thepresent invention, it is preferred that a tilt conveyor in accordancewith the present invention be used as the first or receiving conveyorfor accepting items delivered at a right angle. The tilting receivingconveyor is particularly preferred when the product items are fragile orbreakable items.

The tilting receiving conveyor of the present invention provides a wayto receive items delivered at a right angle to the receiving conveyor ina gentle manner avoiding hard impacts or dropping of the items. This isespecially important, for example, for loading breakable baked itemssuch as cookies, chips or graham crackers that can easily crack or breakif subjected to minimal impact forces. The tilt conveyor may bepivotally mounted for rotation about the line that centrally divides thewidth of the upper surface of the receiving tilt conveyor. The tiltconveyor may tilt at the same or substantially the same angle as thedrop gate while receiving strips of items delivered by the right angleoverhead conveyor. By tilting at the same or about the same angle as thedrop gate, the surface of the tilt conveyor becomes at leastsubstantially aligned with the surface of the opened drop gate.Accordingly, the items delivered by the overhead conveyor gently slideonto the surface of the receiving tilt conveyor that is aligned with thesurface of the drop gate. This minimizes any impact that may occur bysliding items from the tilted drop gate onto horizontally positionedreceiving conveyors used in the previously mentioned “candy bar”technology.

The tilt conveyor of the present invention further comprises a backstopthat prevents items from moving forward past the receiving tilt conveyorsurface and sliding off the receiving conveyor while the conveyorremains in its tilted position receiving the delivered groups of items.The backstop may be located adjacent to the tilt conveyor or may beattached to the receiving tilt conveyor. If the backstop is attached tothe conveyor, the backstop tilts together with the conveyor. If thebackstop is not attached to the tilt conveyor and is located adjacent toit, the backstop is usually located below the horizontal position levelof the tilt conveyor so that it becomes at least substantially alignedwith the edge of the tilt conveyor in its tilted position. In thepreferred embodiment, the backstop is not attached to the tilt conveyorand is located adjacent to the tilt conveyor.

The position of the backstop is adjusted so that when the sliding itemsreach the backstop, the items are positioned substantially in the middleof the receiving conveyor. Thus, the center of gravity of each of theitems loaded onto the tilted receiving conveyor is located substantiallydirectly above the line centrally dividing the width of the receivingconveyor, and at the rotation line of the tilt conveyor. The position ofthe items on the tilted conveyor is important so that the items do notslide, tilt or move upon the rotation of the tilt conveyor back to itsoriginal horizontal position.

In preferred embodiments, the width of the tilt conveyor is slightlynarrower than the length of individual items received by the tiltconveyor. This allows the items stopped by the backstop to be easilypositioned in the middle of the conveyor belt as described above. Assoon as the items are loaded onto the tilt conveyor and the tiltconveyor rotates back to its original horizontal position, the tiltconveyor accelerates forward very quickly to rapidly deliver a loadedstrip of items to the next conveyor in the series of infeed systemconveyors. The tilt conveyor has to move forward very quickly to clearthe way for the next strip of items delivered by the right angleoverhead conveyor.

The profile of the conveyor belt of the receiving tilt conveyor can beflat or of any conventionally known shape. However, conveyor beltshaving regularly spaced rounded lugs or teeth are preferred. The teethare regularly spaced from each other with the distance between thecenters or the tops of the teeth being substantially equal to the widthof an individual item from the strip of items received by the tiltconveyor. The radius or height of each tooth should be slightly greaterthan the height or thickness of the individual items.

The movement of the tilt conveyor and the overhead delivery conveyor aresynchronized so that each individual item from the strip of itemsdelivered by the overhead conveyor is loaded between the teeth of thetilt conveyor belt. Upon discharging the strip of items onto the tiltconveyor each of the individual items occupies space between the teethso that the front edge of each item is leaning on one of the teeth andthe back edge of each item is resting against or near the bottom of thenext tooth. The teeth have primarily two purposes. First, the teethallow for rapid acceleration of the tilt conveyor. Supporting the backedge of each item at the bottom of the following tooth prevents items,especially the last few items in a strip, from sliding backwards uponrapid forward acceleration of the tilt conveyor. Second, the lugs helpto align misoriented items to facilitate handling of the items anduniform discharging to the following conveyors.

The tilt conveyor delivers batches or strips of items to the nextconveyor and discharges the items to the next conveyor in a flatarrangement. Flatly arranged items are than arranged into a solid streamof items by two or more gap closing belts or conveyors that completelyor substantially eliminate gaps between the strips of items. The gapclosing belts operate at the same velocity as the tilt conveyor whenthey receive the strip of items and then decelerate to a slower speedwhile discharging the strips to the following conveyor belt. The firstgap closing belt may even operate at slightly higher speed than the tiltconveyor while accepting items from the tilt conveyor. By moving with aslightly higher speed the first gap closing conveyor removes itemsquickly so that the lugs do not touch the trailing end of the itemsloaded onto the first gap closing conveyor. This is particularlyimportant when the delivered items are fragile or easy to brake.

The gap closing belt may include gap closing shuttles that eliminate anygaps in the stream of items due to missing items. A solid stream ofitems is then broken or separated into groups of predetermined number byextending a retractable noser and momentarily increasing the speed of adownstream conveyor belt. The predetermined amount of items may becounted by a counting means or strip length measuring means, such as anoverhead counter, a photoelectric eye, a vision system or any otherknown counting or length measuring means. When the trailing piece for agroup is determined by the counting means or other measuring means to beon the downstream conveyor, the retractable noser extends while thedownstream conveyor momentarily increases in speed, thus separatinggroups of items.

The separated groups are then shingled by placing them on a slowermoving conveyor, and the gap between the groups is increased by two ormore successive gap separating conveyors. Then, regularly separatedgroups are feed to the item input end of the stacking conveyor. The gapsor intervals between the groups are chosen to synchronize the arrival ofthe first item in each shingled group to the delivery end of thestacking conveyor at the time when the lowering arms are in their upperposition and ready to receive the group and begin the stacking cycle.Alternatively, the lowering arms may be stopped and held in the upperposition at the end of one stacking cycle waiting for the arrival of anew group of items.

The stacking apparatus can be easily adjusted to form stacks of variousheights, it tolerates irregularities in a shingled arrangement, i.e., itis not sensitive to irregularly placed or crooked crackers, or evensmall gaps between crackers within the same group that forms a singlevertical stack, and it is also insensitive to broken crackers within theshingled group of crackers. Regular stacks will be formed from ashingled arrangement containing minor irregularities as discussed above,and these irregularities will be cured during the stacking cycleproducing regular vertical stacks. Moreover, where a shingled groupcontains too many broken individual items such as broken crackers, or agap between crackers is too large to form a regular stack, the stackingapparatus of the invention may, occasionally, produce, in such a case,an irregular stack. However, it does not get jammed and will not requireinterruption of the stacking process.

FIG. 1 a schematically illustrates the stacking apparatus of the presentinvention for stacking groups of shingled items such as graham crackersinto vertical stacks of predetermined number of items in each stack. Thestacking apparatus 10 receives groups of shingled items 12 that areplaced on a stacking conveyor belt 14, i.e on its item input end 16, andtransported to its item delivery end or output end 18. The stackingconveyor belt 14 is usually combined with an infeed system shown in.FIG. 2, which is located upstream of the input end 16 of the upperconveyor 14. The infeed system groups items in groups of desired number,places them in a shingled arrangement, separates the groups and deliversthe groups in regular intervals to the input end 16.

A set of lowering arms 20 is located adjacent to the stacking conveyorbelt 14, with at least one arm located adjacent to each side of conveyorbelt 14. As a group of shingled items approaches the item delivery end18 of the conveyor belt 14, the lowering arms are aligned in their upperposition to be slightly below the upper surface of the stacking conveyorbelt 14 and extend beyond the item delivery end 18 of the stackingconveyor belt 14. As the first or leading item 13 of the group 12 comesinto contact with lowering arms 20, the forward movement of the firstitems is slowed down and then is completely stopped by the lowering arms20 and the guide 22.

The guide 22 helps to prevent forward movement of every item in a groupand helps to guide them into forming a vertical stack. After the firstitem 13 of the group 12 is placed on or transferred to the lowering arms20, the lowering arms, attached to cranks 26 a and 26 b, are moved orswung down as shown in FIG. 1 b by cranks 26 a and 26 b in a continuousmotion lowering the first item 13 to a lower stacking platform 31. Whilethe first item is being lowered, the items following the first item arecontinuously placed on top of each other, i.e. each item is placed ontop of a previous item forming a vertical stack 30. During the loweringoperation, cranks 26 a and 26 b travel continuously in acounter-clockwise circular motion. A stop plate 25 prevents any backwardmovement of the stack 30 as the lowering arms travel downwardly andbackwardly, thereby forming a substantially vertically aligned stack ofitems.

After reaching the lower stacking level and placing a stack 30 on alower stacking platform 31 lowering arms are retrieved or retracted asshown in FIG. 1 c by cranks 26 a and 26 b downwards and backwardsreleasing the stack 30. The pushing plate 28 pushes the formed stack 30horizontally, away from the stacking conveyor 14 and places it ontoanother conveyor 32, which may have compartments or flap fingers 32 a.As soon as stack 30 is supported by stacking platform 31, the loweringarms continue to retract backward and downward, and then upward in orderto reach the original upper position to receive the next incoming groupof shingled items for stacking this next group into a vertical stack.Thus, after a complete release of the stack 30, the lowering arms maycontinue to move downward and backward, then backward and upward, andthen upward and forward to its uppermost position so that the cranks 26a and 26 b complete a full circle. Accordingly, for the lowering arms 20to receive a new group of shingled items 12, thus completing thestacking cycle, the cranks 26 a and 26 b pivot about an axis at theirpulleyed ends to complete a 360° path or full circle.

In another embodiment, the lowering arms 20 may be held in a downwardposition after releasing the vertical stack 30 for a time sufficient toremove the stack 30, and then swung back to their original uppermostposition by cranks 26 a and 26 b moving in the opposite direction, i.e.in a clockwise direction, and reciprocating their original semi-circularpath.

The lowering arms may be driven by a separate motor (not shown) notconnected to the other driving means of the infeed system. The shaft ofthe motor may be drivingly connected to a pulley 34 a that drives a belt36 which is drivingly connected to pulleys 34 b and 34 c. The pulleys 34b and 34 c may be rotatably mounted on a support 35, and drivinglyconnected to an end of rotatable cranks 26 b and 26 a, respectively. Thebelt 36 rotates pulleys 34 c and 34 b which rotate cranks 26 a and 26 b,respectively which causes the lowering arms 20 pivotally attached to thecranks 26 a and 26 b to move in counterclockwise direction. Inembodiments of the invention, the pulleys 34 a, 34 b, and 34 c, may bereplaced by gears, and the belt 36 may be replaced by a chain drive.

The infeed system 38 shown on FIG. 2 comprises a series of conveyorsmoving in the same direction. The conveyors are moved by variable speedelectric motors. The infeed conveyor 40 receives items, in a flat orslightly angled arrangement, depending on the profile of the belt ofconveyor 40, as they arrive from another location. Conveyor 40 isdesigned to accept items delivered in batches, strips or rows at a rightangle and transport them to the conveyor 42, moving at a variable speedto reduce gaps between the strips of items. Conveyor 42 quickly acceptsbatches of items delivered by conveyor 40 so that conveyor 40 is clearedto receive the next batch of items. Conveyor 42 comprises two conveyorbelts 42 a and 42 b and a gap closing shuttle 44, for reducing gapsbetween the items that exist in the item stream due to missing ormisplaced items. After the gaps are reduced the stream of items istransported to the next conveyor belt 46, moving at variable speed.Conveyor 46 completely closes gaps between the strips of items. Conveyor46 also comprises two belts 46 a and 46 b and another gap reducingshuttle 48. The shuttle 48 completely eliminates any remaining gaps dueto missing items, and the items are delivered to the end of the conveyorbelt 46 as a continuous stream. In some cases it is possible to closeall gaps with only one gap closing conveyor.

A solid stream of items then flows to the next conveyor 49 comprising aretracting noser 50 at the delivery end of the conveyor belt 49, toallow the stream of items to be separated into groups. An optionallaunch roller 51 located at the end of conveyor 49 prevents tilting ofthe flat items and assures that the items exit conveyor 49 insubstantially horizontal position and form shingled groups upon enteringconveyor 52 without turning on their other side. The flat items arecounted by an overhead sensor or counter (not shown) and enter the nextconveyor belt 52 in counted groups. Conveyor belt 52 moves with a speedslower than the speed of the conveyor belt 49, so that the items enterconveyor belt 52 slightly overlapped with each other and form groups ofshingled items. When the desired count or number of items has beendetected, the noser 50 extends momentarily preventing additional itemsfrom entering conveyor 52. At the same time, conveyor 52 increases itsspeed for a moment to move the formed group of shingled items forwardthus forming a gap between the group of shingled items and the nextincoming group. The groups of shingled items are then transported to yetanother conveyor belt 54. By extending separating shuttle 56, the speedof conveyor belt 54 may be momentarily increased while a complete groupof shingled items is supported by conveyor belt 54. The momentaryincrease in speed creates a greater separation of the groups.

Groups of products separated by the gaps of predetermined length betweenthe groups enter the stacker feed conveyor 58 which delivers separatedgroups of shingled items to the input end of the stacking conveyor 14.The gaps between the shingled groups entering the stacking conveyor 14has to be of sufficient length to allow the lowering arms 20 of thestacker 10 to complete one full stacking cycle with one group of itemsbefore the next group arrives at the delivery end of the stackingconveyor 14. The conveyors comprising shuttles and the nosers operatewith the aid of automatic take-ups 60(a-g) known in the art andconventionally used with conveyors comprising shuttles or nosers.

The gaps between the groups and the speed of the stacking conveyor 14has to be synchronized with the lowering arm cycle time, so that eachgroup of items arrives at the delivery end of the stacking conveyor 14at or after the exact moment when the lowering arms 20 are located inthe upper position ready to receive the bottom item of the arrivinggroup. Meanwhile, the speed of the lowering arms 20 is adjusted to keeppace with the flow of the groups of shingled items entering the system.

The infeed system 38 for the stacking apparatus 10 is comprised ofseveral conveyors arranged in a series in such a manner that the groupsof items are shingled and delivered to the stacking apparatus 10 atpredetermined time intervals. If the items fed to the infeed system 38arrive at the infeed system 38 moving in the same direction as theinfeed system conveyor flow, conveyor 42 may be the first conveyor ofthe infeed system 38 and conveyor 40 may not be needed for the infeedsystem. If the items arrive in a direction perpendicular to the flow ofthe conveyors in the infeed system 38, i.e. at a right angle to theinfeed system flow direction, the first conveyor of the infeed system isconveyor 40, specifically adopted to accept groups of batches of itemsarriving at a right angle to the flow of the infeed system 38.

As illustrated in FIG. 3 strips or batches of items 68 are deliveredfrom another location, such as an oven, by the strip conveyor 70transporting strips of products 68 at a right angle to the infeed systemflow. The strip conveyor 70 is positioned perpendicularly to theconveyor 40 accepting batches or strips of items 68 from strip conveyor70. Strip conveyor 70 usually delivers strips of items to several infeedsystems 10, 10 a and several others (not shown) arranged substantiallyparallel to each other. Conveyor 70 comprises a series of conveyor belts70 a, 70 b (and others not shown) each of which comprises a drop gate 72a, 72 b and several others (not shown) located near the front edges 74a, 74 b etc. of the conveyors 70 a, 70 b, etc. and away from the backedges 76 a, 76 b, etc., of conveyors 70 a, 70 b, etc. The number of dropgates correspond to the number of parallel infeed systems.

When conveyor 40 is ready to accept a batch or a strip of items, thedrop gate 72 a tilts downward towards the conveyor 40, creating a gap inthe series of conveyors 70 between conveyor 72 a and 72 b. The drop gate72 a tilts at an angle so that the forward edge 74 a of the tiltedconveyor 72 a is located slightly above the belt of conveyor 40. At thesame time, back edge 76 b of the conveyor 70 b may tilt upward to widenthe gap between conveyors 70 a and 70 b for easier access of the stripof items 68 to conveyor 40. The strip of items 68 moves via tilted dropgate 72 a toward conveyor 40 and through the gap and is discharged ontoconveyor 40 upon reaching the belt of conveyor 40. As soon as the stripof items is discharged from conveyor 70 onto conveyor 40, the drop gate72 a moves upward bringing the drop gate in a substantially horizontalposition and closing the gap in the conveyor 70. The next strip of items68 a continues to move onto conveyor 70 to one of the following infeedsystems. Meanwhile, the strip of items discharged onto conveyor 40 movesonto the next conveyor 42 of the infeed system clearing conveyor 40. Assoon as conveyor 40 is cleared of the strip of items, conveyor 40 isready to accept the next strip of items delivered at a right angle byconveyor 70. At this point, the drop gate 72 a will drop downward andthe next strip of items will be discharged onto conveyor 40.

When items delivered to conveyor 40 are breakable items, conveyor 40,the first conveyor in the series of conveyors in the infeed system is atilt conveyor as shown in FIG. 4. When tilt conveyor 40 accepts stripsof items from conveyor 70, the tilt conveyor 40 tilts from its originalsubstantially horizontal position (shown by broken lines) at an anglecorresponding to the angle of the tilted drop gate 72 a so that thetilted drop gate 72 a and tilted conveyor 40 are substantially parallelto each other and tilt conveyor 40 is positioned as an extension of thetilted drop gate or is in the substantially same plane as the tilteddrop gate. The strip of items 68 is gently discharged from the tilteddrop gate 72 a onto tilted conveyor 40 by sliding onto conveyor 40.

A backstop 78 is located adjacent to the tilt conveyor 40 to preventsliding items 68 from sliding past the conveyor 40. The backstop 78 maybe cushioned at its end for cushioning of the sliding items. When theitems reach the backstop 78, the center of gravity of each of the itemsin the strip of items 68 is positioned substantially directly above thecentral line 80 of the conveyor belt 40. The axis of rotation of tiltconveyor 40 is approximately at the center of gravity of the strip ofitems 68. Such positioning of the items prevents items from sliding ortilting during rotation of the conveyor 40 to the horizontal position.As soon as the items are discharged from the tilted end of conveyor 70onto conveyor 40, the tilt conveyor 40 rotates back to assume itsoriginal substantially horizontal position and rapidly acceleratesforward to deliver the strip of items 68 loaded onto conveyor 40 to thenext conveyor 42 in the series of conveyors in the infeed system 10.

The profile of the tilt conveyor 40 may be flat or may contain bumps orteeth 90 as shown in FIG. 5. Teeth 90 are spaced from each other so thatthe distance between the center or top of each tooth and the next toothis substantially the same as the width of an individual item 92 in astrip of items 68. Upon discharging the strip of items 68 onto conveyor40, each of the individual items occupies space between the teeth 90,with the front or leading edge 94 of each of the items 92 leaning on oneof the teeth 90 and the back edge 96 of each item 92 resting against orabutting or near the bottom of the next tooth 90. Such arrangement ofthe items on conveyor 40 prevents items, especially the last few itemsin a strip 68, from sliding backwards upon rapid acceleration ofconveyor 40. Also, since the distance between the centers of the teethis substantially equal to the width of individual items, the items aredischarged onto the next conveyor 42 in substantially flat arrangementwithout overlapping.

The stacking apparatus may be used to stack a wide variety of itemsdelivered to the stacker conveyor in shingled arrangement and also maybe used to stack or transport individual items from an upper conveyor toa lower level. The method utilizing the stacking-apparatus allows for avery gentle handling of the items by slowing down the forward movementof the items and completely stopping the forward movement of the itemswithout heavy impact of the items against stopping gates or otherstopping devices and without any impact of dropping of the items.Jamming of the system is extremely unlikely because the need for anymetering gates normally used in known stacking systems is eliminated.Usually, vertical stacks of a predetermined number of items are formedfrom large vertical stacks by metering or counting a desired number ofitems from the bottom of the vertical stack and pushing a smallervertical stack containing a counted number of items through a meteringgate. The height of the metering gate is preset so that the upper bar ofthe gate is slightly higher than the height of the smaller verticalstack containing a predetermined number of items. As a result, thesmaller vertical stack can pass through the gate. However, stacks havinga height of the smaller vertical stack plus one additional item, wouldhave the additional item stopped by the gate and only the desired numberof items would pass through the gates. For example, if the desired smallstack should contain 12 items, the height at which the upper bar of themetering gate is located would be above the height of 12 items, butbelow the height of 13 items, so that the 13th item is stopped by theupper bar. However, the heights of individual items in the stack mayvary, such as, for example, in the case where the stacked items are fooditems such as crackers. The height of the smaller stack with apredetermined number of items may be higher than the anticipated ordesired height. In this case, the metering gates would cause breakage orscraping of the top item which leads to a severe problem of stackingapparatus jamming. The need for metering of a desired number of itemsfrom a large vertical stack and using any kind of metering gates iscompletely eliminated when using the stacking apparatus of the presentinvention. Accordingly, reducing or even elimination of jamming isachieved with the stacking apparatus of the present invention, whichleads to a more economical process and easy maintenance of the stackingapparatus.

1. An infeed system for a stacking apparatus comprising a series of atleast four conveyors wherein: at least one of said four conveyorscomprises a gap-closing shuttle for reducing gaps between items in astream of items, at least one of said four conveyors comprises agap-reducing shuttle for eliminating any remaining gaps between theitems, at least one of said four conveyors comprises a retracting noserfor separating the items into groups of items, and at least one of saidfour conveyors comprises a group-separating shuttle for creating agreater separation of predetermined length between the groups of items.2. An infeed system as claimed in claim 1, further comprising areceiving conveyor for receiving items delivered at substantially aright angle to the flow of the series of at least four conveyors in saidinfeed system.
 3. An infeed system as claimed in claim 2, wherein saidreceiving conveyor is a tilt conveyor.
 4. An infeed system as claimed inclaim 3, further comprising a backstop, wherein said backstop is locatedadjacent to said tilt conveyor.
 5. An infeed system as claimed in claim3, wherein said tilt conveyor comprises a conveyor belt.
 6. An infeedsystem as claimed in claim 5, wherein said conveyor belt is a profilebelt.
 7. An infeed system as claimed in claim 3, wherein said tiltconveyor further comprises a backstop attached to said tilt conveyor. 8.An infeed system as claimed in claim 3, further comprising an overheadtransfer conveyor positioned above and substantially at a right angle tosaid tilt conveyor, wherein said tilt conveyor is pivotally mounted fortilting and alignment with the surface of a drop gate of said overheadtransfer conveyor, and for pivotably returning to a horizontal positionafter receiving the items from said overhead transfer conveyor.
 9. Aninfeed system as claimed in claim 8, wherein at least one end of aconveyor in the series of conveyors is aligned with said tilt conveyorin its horizontal position.
 10. An infeed system as claimed in claim 4,wherein the backstop is located below a horizontal position of said tiltconveyor so that it becomes at least substantially aligned with an edgeof said tilt conveyor.
 11. An infeed system as claimed in claim 8,wherein said overhead transfer conveyor comprises a series of conveyorbelts, each of which comprises a drop gate.
 12. An infeed system asclaimed in claim 11, wherein a drop gate tilts downwards to said tiltconveyor, thereby creating a gap in said series of conveyor belts. 13.An infeed system as claimed in claim 3, wherein said tilt conveyorcomprises teeth that are spaced apart at a distance that issubstantially the same as the width of an individual item in a strip ofitems.
 14. An infeed system as claimed in claim 1, wherein said itemscomprise cookies, chips, or graham crackers.
 15. An infeed system asclaimed in claim 1, further comprising an overhead sensor for countingthe items.
 16. An infeed system as claimed in claim 1, furthercomprising a launch roller at the end of a conveyor comprising theretracting noser.
 17. An infeed system as claimed in claim 1, wherein aconveyor comprising the group-separating shuttle moves at a slower speedthan a conveyor comprising the retracting noser, thereby forming groupsof shingled items.